• Asian-Australasian Journal of Animal Sciences
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• v.22 no.11
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• pp.1513-1520
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• 2009

Forty-six Holstein heifers were used in a completely randomized design and assigned to 1 of 2 treatments to evaluate the effects of 2 diets varying in ruminal fermentable carbohydrate sources, namely ground corn (GC) and rolled wheat (RW), on metabolism and performance of primiparous cows in the periparturient period. The heifers were fed diets as a total mixed ration (TMR) with similar energy and crude protein content including i) 18.57% GC, or ii) 18.57% RW from -24.13${\pm}$7.73 d relative to expected calving until calving. After calving, all animals received the same lactation diet until 28 d. Animals were group fed from the beginning of the study to -7 d relative to expected calving, fed individually from d -7 to 7 days in milk (DIM), and again group fed to 28 DIM. The pre-partum diets affected (p<0.05) dry matter intake (DMI), energy intake, energy balance (EB) and urinary pH during the last week pre-partum. There was no effect of pre-partum carbohydrate source on overall plasma concentration of glucose, nonesterified fatty acid (NEFA), $\beta$-hydroxybutyrate (BHBA), albumin, triglyceride (TG), cholesterol, aspartate aminotransferase (AST), insulin, and cortisol during the periparturient period. Cows fed the RW diet during the pre-partum period had greater calcium for the first week (p<0.05) and during 28 d (p = 0.08) of lactation compared with heifers fed the GC diet. Primiparous cows fed the RW diet produced greater milk protein content and yield (p<0.05). Primiparous cows fed the RW diet had lower milk urea nitrogen (MUN) and somatic cell count (SCC) than cows fed the GC diet (p<0.05). The results of this study show that feeding pre-partum diets with a rapidly fermentable source of starch but low energy content can improve animal metabolism and performance and smooth the transition of primiparous Holstein cows from gestation to lactation.

• Animal Bioscience
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• v.34 no.4
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• pp.759-769
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• 2021

Objective: This study aimed to investigate the effect of stocking density on the behavior, productivity, and metabolism of periparturient Holstein cows as well as calf performance. Methods: A total of 48 periparturient cows were randomly assigned into three groups at 28 days (±3 days) before their expected calving date. The stocking densities of the groups, relative to the standard cubicle and feed bunk number, were i) 80% (13 cows), ii) 100% (16 cows), and iii) 120% (19 cows). Lying and rumination behavior was recorded using electronic data loggers and HR-Tags from d -21 ("d-" means days before calving) until the calving date, d 0. Lying time was assessed to determine the diurnal total hours spent lying per day. Rumination time was averaged in 2 hours interval periods over 24 hours during the experimental period. Results: Cows in the 80% group spent more time lying and ruminating between d -21 and d -7 and tended to ruminate more between d -14 and d 0. Calcium levels tended to be higher for cows in the 80% group, no other observable differences were found in monitored blood parameters. Moreover, 3.5% fat corrected milk and energy corrected milk yields were higher in 80% group in the first month of lactation. No other observable differences were found in the yield and composition of colostrum and milk in the first 10 months of lactation. The growth and performance of calves in the first week of life was not affected by stocking density of the dams. Conclusion: We concluded that lower stocking density may increase lying and ruminating behavior of prepartum Holstein cows. However, this did not translate into improved productivity and metabolism.

• Journal of Animal Science and Technology
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• v.60 no.12
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• pp.31.1-31.10
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• 2018

Background: Research on loci influencing milk production traits of dairy cattle is one of the main topics of investigation in livestock. Many genomic regions and polymorphisms associated with dairy production have been reported worldwide. In this context, the purpose of this study was to identify candidate loci associated with milk yield in Argentinean dairy cattle. A database of candidate genes and single nucleotide polymorphisms (SNPs) for milk production and composition was developed. Thirty-nine SNPs belonging to 22 candidate genes were genotyped on 1643 animals (Holstein and Holstein x Jersey). The genotypes obtained were subjected to association studies considering the whole population and discriminating the population by Holstein breed percentage. Phenotypic data consisted of milk production values recorded during the first lactation of 1156 Holstein and 462 Holstein ${\times}$ Jersey cows from 18 dairy farms located in the central dairy area of Argentina. From these records, 305-day cumulative milk production values were predicted. Results: Eight SNPs (rs43375517, rs29004488, rs132812135, rs137651874, rs109191047, rs135164815, rs43706485, and rs41255693), located on six Bos taurus autosomes (BTA4, BTA6, BTA19, BTA20, BTA22, and BTA26), showed suggestive associations with 305-day cumulative milk production (under Benjamini-Hochberg procedure with a false discovery rate of 0.1). Two of those SNPs (rs43375517 and rs135164815) were significantly associated with milk production (Bonferroni adjusted p-values < 0.05) when considering the Holstein population. Conclusions: The results obtained are consistent with previously reported associations in other Holstein populations. Furthermore, the SNPs found to influence bovine milk production in this study may be used as possible candidate SNPs for marker-assisted selection programs in Argentinean dairy cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.5
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• pp.646-650
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• 2001

The effect of feeding concentrate mixture devoid of grain on the performance of crossbred dairy cows was studied. Twelve crossbred cows of first/second lactation were randomly distributed into two equal groups. The animals of group 1 were fed on a concentrate mixture containing 30% maize grain whereas, the cows of group 2 were offered a concentrate mixture where grain was completely replaced with deoiled rice bran (DORB) and molasses. Wheat straw was given ad libitum to the cows of both the groups. The feeding was continued for 112 days. The intake of dry matter, CP and TDN were similar in both the groups. Digestibility of DM, OM, EE, NDF and ADF were also comparable between the groups. The average daily fat corrected milk (FCM) yield was 7.70 kg and 7.43 kg in group 1 and 2, respectively. The chemical composition of milk (protein, fat and total solids) also remained unaffected. The animals of both the groups gained 9-10 kg body weight which indicates that both the diets were nutritionally adequate and grain can be successfully replaced with DORB and molasses from the diet to sustain about 6-7 kg FCM production.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.966-975
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• 2015

Heat production in ruminants follows a diurnal pattern over the course of a day peaking 3 hours following afternoon feeding and then gradually declining to its lowest point prior to morning feeding. In order to clarify the cooling period most effective in reducing decreases in feed intake and milk production, experiments were carried out based on the diurnal rhythm of heat production and heat dissipation. In experiment 1, the effects of hot environment on milk production were investigated. The animals were kept first in a thermoneutral environment ($20.0^{\circ}C$, 80.0%) for 12 days, they were then transitioned to a hot environment ($32^{\circ}C$, 80.0%) for 13 days before being returned to second thermoneutral environment for a further 12 days. In experiment 2, the effectiveness of daytime cooling or nighttime cooling for improving milk production in hot environment was compared. While ten lactating Japanese Saanen goats (aged 2 years, weighing 41.0 kg) during early lactation were used in experiment 1, ten lactating goats (aged 2 years, weighing 47.5 kg) during mid-lactation were used in experiment 2. The animals were fed 300 g of concentrated feed and excessive amounts of crushed alfalfa hay cubes twice daily. Water was given ad libitum. The animals were milked twice daily. When exposed to a hot environment, milk yield and composition decreased significantly (p<0.05). Milk yield in the hot environment did not change with daytime cooling, but tended to increase with nighttime cooling. Compared to the daytime cooling, milk components percentages in the nighttime cooling were not significantly different but the milk components yields in the nighttime cooling were significantly higher (p<0.05). The results indicate that nighttime cooling is more effective than daytime cooling in the reduction of milk production declines in lactating goats exposed to a hot environment.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.427-438
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• 1996

The suitability of female cattle ($Brahman{\times}Holstein$) and buffaloes (Murrah / Jafarabadi) for work on a sugarcane crusher was tested. The animals were fed chopped sugarcane tops and elephant grass supplemented with rice bran and urea-molasses blocks. In experiment 1, six cattle and six buffaloes, (with three animals seven to eight months pregnant at the start of the experiment in each group), worked individually, alternate weeks for 90 minutes a day for 6 d/week. Within the 90 min, cattle did more work than buffaloes (p < 0.05), and non-pregnant animals did more than pregnant animals, but cattle crushed significantly (p < 0.05) more cane per day than buffaloes. During work animals lost weight, but gained the weight back during resting weeks, when fodder intakes were higher. There were no significant differences in live weight change and fodder intakes between pregnant and non-pregnant animals during the six weeks. In experiment 2, four pairs of lactating cows and buffaloes crushed sugarcane for 3 h/d, 6 d/week for three weeks. Work done was higher in cattle than buffaloes, but cane crushed was marginally lower. All animals lost weight during work, particularly in the first week, but gained weight during the week after work. Daily milk yield was lower during the working weeks ($-0.55{\pm}0.15kg$) than in the week before work. Butter fat yield showed no significant change. One buffalo showed ovarian activity and oestrus behaviour during the work. Two cows showed ovarian activity within one month after the work. It was concluded that pregnant and lactating cows and buffaloes can effectively operate a cane crusher, however a temporary reduction in milk yield can be expected in the working period, and ovarian activity may be suppressed.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1216-1222
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• 2012

Somatic cells count (SCC), milk yield (MY) and pedigree information of 2,791 first lactation cows that calved between 1990 and 2010 on 259 Thai farms were used to estimate genetic parameters and trends for SCC and its genetic association with MY. The SCC were log-transformed (lnSCC) to make them normally distributed. An average information-restricted maximum likelihood procedure was used to estimate variance components. A bivariate animal model that considered herd-yr-season, calving age, and regression additive genetic group as fixed effects, and animal and residual as random effects was used for genetic evaluation. Heritability estimates were 0.12 (SE = 0.19) for lnSCC, and 0.31 (SE = 0.06) for MY. The genetic correlation estimate between lnSCC and MY was 0.26 (SE = 0.59). Mean yearly estimated breeding values during the last 20 years increased for SCC (49.02 cells/ml/yr, SE = 26.81 cells/ml/yr; p = 0.08), but not for MY (0.37 kg/yr, SE = 0.87 kg/yr; p = 0.68). Sire average breeding values for SCC and MY were higher than those of cows and dams (p<0.01). Heritability estimates for lnSCC and MY and their low but positive genetic correlation suggested that selection for low SCC may be feasible in this population as it is in other populations of dairy cows. Thus, selection for high MY and low SCC should be encouraged in Thai dairy improvement programs to increase profitability by improving both cow health and milk yield.

• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.178-185
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• 2013

This study evaluated the effects of milk yield on the postpartum health and reproductive performance of dairy cows. In total, data were collected from 1,060 cows on six dairy farms, including their milk production, body condition score (BCS), postpartum disorders, and reproductive performance. The lactation data were grouped based on the 305-day milk yield into control (< 10,000 kg, n = 445) and high milk yield (${\geq}$ 10,000 kg, n = 615) groups. The milk fat and protein, and BCS were lower during the first 5 months postpartum in the high milk yield group compared with the control group (p < 0.01). Ovarian cysts were more frequent (p < 0.0001) in the high milk yield group (28.6%) than in the control group (15.3%), whereas endometritis tended to be less frequent in the high milk yield group (29.6%) than in the control group (35.1%, p = 0.06). A higher proportion of cows tended to receive reproductive hormones (p = 0.06) in the high milk yield group (62.4%) than in the control group (56.6%). The probability of a pregnancy after first insemination tended to be lower (odds ratio = 0.78, p = 0.07) in the high milk yield group (30.2%) than in the control group (35.2%). Furthermore, the hazard of pregnancy by 210 days in milk was lower in the high milk yield group (hazard ratio = 0.84, p = 0.04) than in the control group, which resulted in a 20-day increase in the median interval to pregnancy. In conclusion, high milk yield was related to lower milk fat and protein, lower BCS, an increased incidence of ovarian cysts, and increased use of reproductive hormones, which resulted in decreased reproductive performance of dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1763-1769
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• 2003

Two experiments were conducted to examine the production and quality of cassava hay and its utilization in diets for dairy cows. In experiment I, a $2{\times}2$ Factorial arrangement in a randomized complete block design with 4 replications was carried out to determine the effects of different initial (IC) and subsequent cutting (SC) on yield and composition of cassava plant. The results revealed that cassava could produce from 4 to 7 tonne of DM and 1.2 to 1.6 tonne of CP for the first six months after planting. CP content in cassava plant ranged from 20.8 to 28.5% and was affected by different SC regimes. Condensed tannin in cassava foliage ranged from 4.9 to 5.5%. Initial cutting at 2 months with subsequent cutting at 2 month intervals was the optimal to obtain high dry matter and protein yield. In the second experiment, five crossbred Holstein-Friesian cows in mid lactation with an initial live-weight of 505${\pm}6.1kg$ and average milk yield of 10.78${\pm}1.2kg/d$ were randomly assigned in a $5{\times}5$ Latin square design to study the effects of 2 levels of CH (1 and 2 kg/hd/d) and concentrate (1 to 2 kg of milk and 1 to 3 kg of milk) on milk yield and milk composition. The results showed that cassava hay increased rumen $NH_3-N$ and milk urea nitrogen (MUN) (p<0.05). Cassava hay tended to increase milk production and 4% FCM. Milk protein increased in cows fed cassava hay (p<0.05). Moreover, cassava hay could reduce concentrate levels in dairy rations thus resulting in increased economic returns. Cassava hay can be a good source of forage to reduce concentrate supplementation and improve milk quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.177-190
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• 2011

This study was conducted to determine effects of dietary herbaceous peat on in vitro fermentation and milk production in dairy cows. Ruminal pH, gas production, VFA (volatile fatty acid), Ammonia-N, and rumen degradability were examined by the addition of three times over 0, 1, and 5% herbaceous peat with substrate of timothy hay, and the change of rumen fermentation characteristics were evaluated. In 0, 3, 12 and 24 hours cultivation, all treatments did not show a significant difference but the control at 6 hours appeared significantly lower pH compared to 1 and 5% treatments (p<0.05). The gas production of the treatments significantly increased until 12 hours of cultivation compared to control (p<0.05), the rumen ammonia concentration showed a tendency to increase until 24 hours in all treatment groups, and there was no significant difference between treatments. About the rumen degradability, 5% treatment showed higher rumen degradability in all hours than control and 1% treatment (p<0.05). Meanwhile, for in vivo trial, 16 heads of Holstein lactation dairy cows were selected for experiment for four weeks in order to research the change of milk yield, milk compositions and change of somatic cell counts of lactation dairy cows by herbaceous peat feeding. The milk yield of vitamin C and herbaceous peat treatments (T3) was 25.0 kg but the control was 23.2 kg, herbaceous peat treatment (T1) was 23.1 kg, and vitamin C treatment (T2) was 23.4 kg, so there was linear increase effect of milk yield by T3. The partial significance of the milk (fat, milk protein, lactose, MUN and SNF) and change of somatic cell count before and after experiment by the control and treatments about change of milk and somatic cell counts (p<0.05) were recognized. About change of milk in the first half (1~2 weeks) and latter half (3~4 weeks) during four weeks of experiments period, the herbaceous peat supplement treatments showed a tendency of significant decrease of quality of milk protein and SNF. The control and treatments did not show significant change of blood nutrients (total protein, cholesterol, NEFA, BUN), liver function component (AST, GGT) and minerals (Ca, P, Mg) before and after experiment. In summary, it is judged that herbaceous peat feeding for lactation dairy cows would be recommendable based on the results of milk, somatic cell count physiologically.